t_hash.c文件代碼：

#include "redis.h" #include <math.h>/*-----------------------------------------------------------------------------* Hash type API*----------------------------------------------------------------------------*//* Check the length of a number of objects to see if we need to convert a* ziplist to a real hash. Note that we only check string encoded objects* as their string length can be queried in constant time. */ void hashTypeTryConversion(robj *o, robj **argv, int start, int end) {int i;if (o->encoding != REDIS_ENCODING_ZIPLIST) return;for (i = start; i <= end; i++) {if (argv[i]->encoding == REDIS_ENCODING_RAW &&sdslen(argv[i]->ptr) > server.hash_max_ziplist_value){hashTypeConvert(o, REDIS_ENCODING_HT);break;}} }/* Encode given objects in-place when the hash uses a dict. */ void hashTypeTryObjectEncoding(robj *subject, robj **o1, robj **o2) {if (subject->encoding == REDIS_ENCODING_HT) {if (o1) *o1 = tryObjectEncoding(*o1);if (o2) *o2 = tryObjectEncoding(*o2);} }/* Get the value from a ziplist encoded hash, identified by field.* Returns -1 when the field cannot be found. */ int hashTypeGetFromZiplist(robj *o, robj *field,unsigned char **vstr,unsigned int *vlen,long long *vll) {unsigned char *zl, *fptr = NULL, *vptr = NULL;int ret;redisAssert(o->encoding == REDIS_ENCODING_ZIPLIST);field = getDecodedObject(field);zl = o->ptr;fptr = ziplistIndex(zl, ZIPLIST_HEAD);if (fptr != NULL) {fptr = ziplistFind(fptr, field->ptr, sdslen(field->ptr), 1);if (fptr != NULL) {/* Grab pointer to the value (fptr points to the field) */vptr = ziplistNext(zl, fptr);redisAssert(vptr != NULL);}}decrRefCount(field);if (vptr != NULL) {ret = ziplistGet(vptr, vstr, vlen, vll);redisAssert(ret);return 0;}return -1; }/* Get the value from a hash table encoded hash, identified by field.* Returns -1 when the field cannot be found. */ int hashTypeGetFromHashTable(robj *o, robj *field, robj **value) {dictEntry *de;redisAssert(o->encoding == REDIS_ENCODING_HT);de = dictFind(o->ptr, field);if (de == NULL) return -1;*value = dictGetVal(de);return 0; }/* Higher level function of hashTypeGet*() that always returns a Redis* object (either new or with refcount incremented), so that the caller* can retain a reference or call decrRefCount after the usage.** The lower level function can prevent copy on write so it is* the preferred way of doing read operations. */ robj *hashTypeGetObject(robj *o, robj *field) {robj *value = NULL;if (o->encoding == REDIS_ENCODING_ZIPLIST) {unsigned char *vstr = NULL;unsigned int vlen = UINT_MAX;long long vll = LLONG_MAX;if (hashTypeGetFromZiplist(o, field, &vstr, &vlen, &vll) == 0) {if (vstr) {value = createStringObject((char*)vstr, vlen);} else {value = createStringObjectFromLongLong(vll);}}} else if (o->encoding == REDIS_ENCODING_HT) {robj *aux;if (hashTypeGetFromHashTable(o, field, &aux) == 0) {incrRefCount(aux);value = aux;}} else {redisPanic("Unknown hash encoding");}return value; }/* Test if the specified field exists in the given hash. Returns 1 if the field* exists, and 0 when it doesn't. */ int hashTypeExists(robj *o, robj *field) {if (o->encoding == REDIS_ENCODING_ZIPLIST) {unsigned char *vstr = NULL;unsigned int vlen = UINT_MAX;long long vll = LLONG_MAX;if (hashTypeGetFromZiplist(o, field, &vstr, &vlen, &vll) == 0) return 1;} else if (o->encoding == REDIS_ENCODING_HT) {robj *aux;if (hashTypeGetFromHashTable(o, field, &aux) == 0) return 1;} else {redisPanic("Unknown hash encoding");}return 0; }/* Add an element, discard the old if the key already exists.* Return 0 on insert and 1 on update.* This function will take care of incrementing the reference count of the* retained fields and value objects. */ int hashTypeSet(robj *o, robj *field, robj *value) {int update = 0;if (o->encoding == REDIS_ENCODING_ZIPLIST) {unsigned char *zl, *fptr, *vptr;field = getDecodedObject(field);value = getDecodedObject(value);zl = o->ptr;fptr = ziplistIndex(zl, ZIPLIST_HEAD);if (fptr != NULL) {fptr = ziplistFind(fptr, field->ptr, sdslen(field->ptr), 1);if (fptr != NULL) {/* Grab pointer to the value (fptr points to the field) */vptr = ziplistNext(zl, fptr);redisAssert(vptr != NULL);update = 1;/* Delete value */zl = ziplistDelete(zl, &vptr);/* Insert new value */zl = ziplistInsert(zl, vptr, value->ptr, sdslen(value->ptr));}}if (!update) {/* Push new field/value pair onto the tail of the ziplist */zl = ziplistPush(zl, field->ptr, sdslen(field->ptr), ZIPLIST_TAIL);zl = ziplistPush(zl, value->ptr, sdslen(value->ptr), ZIPLIST_TAIL);}o->ptr = zl;decrRefCount(field);decrRefCount(value);/* Check if the ziplist needs to be converted to a hash table */if (hashTypeLength(o) > server.hash_max_ziplist_entries)hashTypeConvert(o, REDIS_ENCODING_HT);} else if (o->encoding == REDIS_ENCODING_HT) {if (dictReplace(o->ptr, field, value)) { /* Insert */incrRefCount(field);} else { /* Update */update = 1;}incrRefCount(value);} else {redisPanic("Unknown hash encoding");}return update; }/* Delete an element from a hash.* Return 1 on deleted and 0 on not found. */ int hashTypeDelete(robj *o, robj *field) {int deleted = 0;if (o->encoding == REDIS_ENCODING_ZIPLIST) {unsigned char *zl, *fptr;field = getDecodedObject(field);zl = o->ptr;fptr = ziplistIndex(zl, ZIPLIST_HEAD);if (fptr != NULL) {fptr = ziplistFind(fptr, field->ptr, sdslen(field->ptr), 1);if (fptr != NULL) {zl = ziplistDelete(zl,&fptr);zl = ziplistDelete(zl,&fptr);o->ptr = zl;deleted = 1;}}decrRefCount(field);} else if (o->encoding == REDIS_ENCODING_HT) {if (dictDelete((dict*)o->ptr, field) == REDIS_OK) {deleted = 1;/* Always check if the dictionary needs a resize after a delete. */if (htNeedsResize(o->ptr)) dictResize(o->ptr);}} else {redisPanic("Unknown hash encoding");}return deleted; }/* Return the number of elements in a hash. */ unsigned long hashTypeLength(robj *o) {unsigned long length = ULONG_MAX;if (o->encoding == REDIS_ENCODING_ZIPLIST) {length = ziplistLen(o->ptr) / 2;} else if (o->encoding == REDIS_ENCODING_HT) {length = dictSize((dict*)o->ptr);} else {redisPanic("Unknown hash encoding");}return length; }hashTypeIterator *hashTypeInitIterator(robj *subject) {hashTypeIterator *hi = zmalloc(sizeof(hashTypeIterator));hi->subject = subject;hi->encoding = subject->encoding;if (hi->encoding == REDIS_ENCODING_ZIPLIST) {hi->fptr = NULL;hi->vptr = NULL;} else if (hi->encoding == REDIS_ENCODING_HT) {hi->di = dictGetIterator(subject->ptr);} else {redisPanic("Unknown hash encoding");}return hi; }void hashTypeReleaseIterator(hashTypeIterator *hi) {if (hi->encoding == REDIS_ENCODING_HT) {dictReleaseIterator(hi->di);}zfree(hi); }/* Move to the next entry in the hash. Return REDIS_OK when the next entry* could be found and REDIS_ERR when the iterator reaches the end. */ int hashTypeNext(hashTypeIterator *hi) {if (hi->encoding == REDIS_ENCODING_ZIPLIST) {unsigned char *zl;unsigned char *fptr, *vptr;zl = hi->subject->ptr;fptr = hi->fptr;vptr = hi->vptr;if (fptr == NULL) {/* Initialize cursor */redisAssert(vptr == NULL);fptr = ziplistIndex(zl, 0);} else {/* Advance cursor */redisAssert(vptr != NULL);fptr = ziplistNext(zl, vptr);}if (fptr == NULL) return REDIS_ERR;/* Grab pointer to the value (fptr points to the field) */vptr = ziplistNext(zl, fptr);redisAssert(vptr != NULL);/* fptr, vptr now point to the first or next pair */hi->fptr = fptr;hi->vptr = vptr;} else if (hi->encoding == REDIS_ENCODING_HT) {if ((hi->de = dictNext(hi->di)) == NULL) return REDIS_ERR;} else {redisPanic("Unknown hash encoding");}return REDIS_OK; }/* Get the field or value at iterator cursor, for an iterator on a hash value* encoded as a ziplist. Prototype is similar to `hashTypeGetFromZiplist`. */ void hashTypeCurrentFromZiplist(hashTypeIterator *hi, int what,unsigned char **vstr,unsigned int *vlen,long long *vll) {int ret;redisAssert(hi->encoding == REDIS_ENCODING_ZIPLIST);if (what & REDIS_HASH_KEY) {ret = ziplistGet(hi->fptr, vstr, vlen, vll);redisAssert(ret);} else {ret = ziplistGet(hi->vptr, vstr, vlen, vll);redisAssert(ret);} }/* Get the field or value at iterator cursor, for an iterator on a hash value* encoded as a ziplist. Prototype is similar to `hashTypeGetFromHashTable`. */ void hashTypeCurrentFromHashTable(hashTypeIterator *hi, int what, robj **dst) {redisAssert(hi->encoding == REDIS_ENCODING_HT);if (what & REDIS_HASH_KEY) {*dst = dictGetKey(hi->de);} else {*dst = dictGetVal(hi->de);} }/* A non copy-on-write friendly but higher level version of hashTypeCurrent*()* that returns an object with incremented refcount (or a new object). It is up* to the caller to decrRefCount() the object if no reference is retained. */ robj *hashTypeCurrentObject(hashTypeIterator *hi, int what) {robj *dst;if (hi->encoding == REDIS_ENCODING_ZIPLIST) {unsigned char *vstr = NULL;unsigned int vlen = UINT_MAX;long long vll = LLONG_MAX;hashTypeCurrentFromZiplist(hi, what, &vstr, &vlen, &vll);if (vstr) {dst = createStringObject((char*)vstr, vlen);} else {dst = createStringObjectFromLongLong(vll);}} else if (hi->encoding == REDIS_ENCODING_HT) {hashTypeCurrentFromHashTable(hi, what, &dst);incrRefCount(dst);} else {redisPanic("Unknown hash encoding");}return dst; }robj *hashTypeLookupWriteOrCreate(redisClient *c, robj *key) {robj *o = lookupKeyWrite(c->db,key);if (o == NULL) {o = createHashObject();dbAdd(c->db,key,o);} else {if (o->type != REDIS_HASH) {addReply(c,shared.wrongtypeerr);return NULL;}}return o; }void hashTypeConvertZiplist(robj *o, int enc) {redisAssert(o->encoding == REDIS_ENCODING_ZIPLIST);if (enc == REDIS_ENCODING_ZIPLIST) {/* Nothing to do... */} else if (enc == REDIS_ENCODING_HT) {hashTypeIterator *hi;dict *dict;int ret;hi = hashTypeInitIterator(o);dict = dictCreate(&hashDictType, NULL);while (hashTypeNext(hi) != REDIS_ERR) {robj *field, *value;field = hashTypeCurrentObject(hi, REDIS_HASH_KEY);field = tryObjectEncoding(field);value = hashTypeCurrentObject(hi, REDIS_HASH_VALUE);value = tryObjectEncoding(value);ret = dictAdd(dict, field, value);if (ret != DICT_OK) {redisLogHexDump(REDIS_WARNING,"ziplist with dup elements dump",o->ptr,ziplistBlobLen(o->ptr));redisAssert(ret == DICT_OK);}}hashTypeReleaseIterator(hi);zfree(o->ptr);o->encoding = REDIS_ENCODING_HT;o->ptr = dict;} else {redisPanic("Unknown hash encoding");} }void hashTypeConvert(robj *o, int enc) {if (o->encoding == REDIS_ENCODING_ZIPLIST) {hashTypeConvertZiplist(o, enc);} else if (o->encoding == REDIS_ENCODING_HT) {redisPanic("Not implemented");} else {redisPanic("Unknown hash encoding");} }/*-----------------------------------------------------------------------------* Hash type commands*----------------------------------------------------------------------------*/void hsetCommand(redisClient *c) {int update;robj *o;if ((o = hashTypeLookupWriteOrCreate(c,c->argv[1])) == NULL) return;hashTypeTryConversion(o,c->argv,2,3);hashTypeTryObjectEncoding(o,&c->argv[2], &c->argv[3]);update = hashTypeSet(o,c->argv[2],c->argv[3]);addReply(c, update ? shared.czero : shared.cone);signalModifiedKey(c->db,c->argv[1]);notifyKeyspaceEvent(REDIS_NOTIFY_HASH,"hset",c->argv[1],c->db->id);server.dirty++; }void hsetnxCommand(redisClient *c) {robj *o;if ((o = hashTypeLookupWriteOrCreate(c,c->argv[1])) == NULL) return;hashTypeTryConversion(o,c->argv,2,3);if (hashTypeExists(o, c->argv[2])) {addReply(c, shared.czero);} else {hashTypeTryObjectEncoding(o,&c->argv[2], &c->argv[3]);hashTypeSet(o,c->argv[2],c->argv[3]);addReply(c, shared.cone);signalModifiedKey(c->db,c->argv[1]);notifyKeyspaceEvent(REDIS_NOTIFY_HASH,"hset",c->argv[1],c->db->id);server.dirty++;} }void hmsetCommand(redisClient *c) {int i;robj *o;if ((c->argc % 2) == 1) {addReplyError(c,"wrong number of arguments for HMSET");return;}if ((o = hashTypeLookupWriteOrCreate(c,c->argv[1])) == NULL) return;hashTypeTryConversion(o,c->argv,2,c->argc-1);for (i = 2; i < c->argc; i += 2) {hashTypeTryObjectEncoding(o,&c->argv[i], &c->argv[i+1]);hashTypeSet(o,c->argv[i],c->argv[i+1]);}addReply(c, shared.ok);signalModifiedKey(c->db,c->argv[1]);notifyKeyspaceEvent(REDIS_NOTIFY_HASH,"hset",c->argv[1],c->db->id);server.dirty++; }void hincrbyCommand(redisClient *c) {long long value, incr, oldvalue;robj *o, *current, *new;if (getLongLongFromObjectOrReply(c,c->argv[3],&incr,NULL) != REDIS_OK) return;if ((o = hashTypeLookupWriteOrCreate(c,c->argv[1])) == NULL) return;if ((current = hashTypeGetObject(o,c->argv[2])) != NULL) {if (getLongLongFromObjectOrReply(c,current,&value,"hash value is not an integer") != REDIS_OK) {decrRefCount(current);return;}decrRefCount(current);} else {value = 0;}oldvalue = value;if ((incr < 0 && oldvalue < 0 && incr < (LLONG_MIN-oldvalue)) ||(incr > 0 && oldvalue > 0 && incr > (LLONG_MAX-oldvalue))) {addReplyError(c,"increment or decrement would overflow");return;}value += incr;new = createStringObjectFromLongLong(value);hashTypeTryObjectEncoding(o,&c->argv[2],NULL);hashTypeSet(o,c->argv[2],new);decrRefCount(new);addReplyLongLong(c,value);signalModifiedKey(c->db,c->argv[1]);notifyKeyspaceEvent(REDIS_NOTIFY_HASH,"hincrby",c->argv[1],c->db->id);server.dirty++; }void hincrbyfloatCommand(redisClient *c) {double long value, incr;robj *o, *current, *new, *aux;if (getLongDoubleFromObjectOrReply(c,c->argv[3],&incr,NULL) != REDIS_OK) return;if ((o = hashTypeLookupWriteOrCreate(c,c->argv[1])) == NULL) return;if ((current = hashTypeGetObject(o,c->argv[2])) != NULL) {if (getLongDoubleFromObjectOrReply(c,current,&value,"hash value is not a valid float") != REDIS_OK) {decrRefCount(current);return;}decrRefCount(current);} else {value = 0;}value += incr;new = createStringObjectFromLongDouble(value,1);hashTypeTryObjectEncoding(o,&c->argv[2],NULL);hashTypeSet(o,c->argv[2],new);addReplyBulk(c,new);signalModifiedKey(c->db,c->argv[1]);notifyKeyspaceEvent(REDIS_NOTIFY_HASH,"hincrbyfloat",c->argv[1],c->db->id);server.dirty++;/* Always replicate HINCRBYFLOAT as an HSET command with the final value* in order to make sure that differences in float pricision or formatting* will not create differences in replicas or after an AOF restart. */aux = createStringObject("HSET",4);rewriteClientCommandArgument(c,0,aux);decrRefCount(aux);rewriteClientCommandArgument(c,3,new);decrRefCount(new); }static void addHashFieldToReply(redisClient *c, robj *o, robj *field) {int ret;if (o == NULL) {addReply(c, shared.nullbulk);return;}if (o->encoding == REDIS_ENCODING_ZIPLIST) {unsigned char *vstr = NULL;unsigned int vlen = UINT_MAX;long long vll = LLONG_MAX;ret = hashTypeGetFromZiplist(o, field, &vstr, &vlen, &vll);if (ret < 0) {addReply(c, shared.nullbulk);} else {if (vstr) {addReplyBulkCBuffer(c, vstr, vlen);} else {addReplyBulkLongLong(c, vll);}}} else if (o->encoding == REDIS_ENCODING_HT) {robj *value;ret = hashTypeGetFromHashTable(o, field, &value);if (ret < 0) {addReply(c, shared.nullbulk);} else {addReplyBulk(c, value);}} else {redisPanic("Unknown hash encoding");} }void hgetCommand(redisClient *c) {robj *o;if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL ||checkType(c,o,REDIS_HASH)) return;addHashFieldToReply(c, o, c->argv[2]); }void hmgetCommand(redisClient *c) {robj *o;int i;/* Don't abort when the key cannot be found. Non-existing keys are empty* hashes, where HMGET should respond with a series of null bulks. */o = lookupKeyRead(c->db, c->argv[1]);if (o != NULL && o->type != REDIS_HASH) {addReply(c, shared.wrongtypeerr);return;}addReplyMultiBulkLen(c, c->argc-2);for (i = 2; i < c->argc; i++) {addHashFieldToReply(c, o, c->argv[i]);} }void hdelCommand(redisClient *c) {robj *o;int j, deleted = 0, keyremoved = 0;if ((o = lookupKeyWriteOrReply(c,c->argv[1],shared.czero)) == NULL ||checkType(c,o,REDIS_HASH)) return;for (j = 2; j < c->argc; j++) {if (hashTypeDelete(o,c->argv[j])) {deleted++;if (hashTypeLength(o) == 0) {dbDelete(c->db,c->argv[1]);keyremoved = 1;break;}}}if (deleted) {signalModifiedKey(c->db,c->argv[1]);notifyKeyspaceEvent(REDIS_NOTIFY_HASH,"hdel",c->argv[1],c->db->id);if (keyremoved)notifyKeyspaceEvent(REDIS_NOTIFY_GENERIC,"del",c->argv[1],c->db->id);server.dirty += deleted;}addReplyLongLong(c,deleted); }void hlenCommand(redisClient *c) {robj *o;if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||checkType(c,o,REDIS_HASH)) return;addReplyLongLong(c,hashTypeLength(o)); }static void addHashIteratorCursorToReply(redisClient *c, hashTypeIterator *hi, int what) {if (hi->encoding == REDIS_ENCODING_ZIPLIST) {unsigned char *vstr = NULL;unsigned int vlen = UINT_MAX;long long vll = LLONG_MAX;hashTypeCurrentFromZiplist(hi, what, &vstr, &vlen, &vll);if (vstr) {addReplyBulkCBuffer(c, vstr, vlen);} else {addReplyBulkLongLong(c, vll);}} else if (hi->encoding == REDIS_ENCODING_HT) {robj *value;hashTypeCurrentFromHashTable(hi, what, &value);addReplyBulk(c, value);} else {redisPanic("Unknown hash encoding");} }void genericHgetallCommand(redisClient *c, int flags) {robj *o;hashTypeIterator *hi;int multiplier = 0;int length, count = 0;if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL|| checkType(c,o,REDIS_HASH)) return;if (flags & REDIS_HASH_KEY) multiplier++;if (flags & REDIS_HASH_VALUE) multiplier++;length = hashTypeLength(o) * multiplier;addReplyMultiBulkLen(c, length);hi = hashTypeInitIterator(o);while (hashTypeNext(hi) != REDIS_ERR) {if (flags & REDIS_HASH_KEY) {addHashIteratorCursorToReply(c, hi, REDIS_HASH_KEY);count++;}if (flags & REDIS_HASH_VALUE) {addHashIteratorCursorToReply(c, hi, REDIS_HASH_VALUE);count++;}}hashTypeReleaseIterator(hi);redisAssert(count == length); }void hkeysCommand(redisClient *c) {genericHgetallCommand(c,REDIS_HASH_KEY); }void hvalsCommand(redisClient *c) {genericHgetallCommand(c,REDIS_HASH_VALUE); }void hgetallCommand(redisClient *c) {genericHgetallCommand(c,REDIS_HASH_KEY|REDIS_HASH_VALUE); }void hexistsCommand(redisClient *c) {robj *o;if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||checkType(c,o,REDIS_HASH)) return;addReply(c, hashTypeExists(o,c->argv[2]) ? shared.cone : shared.czero); }void hscanCommand(redisClient *c) {robj *o;unsigned long cursor;if (parseScanCursorOrReply(c,c->argv[2],&cursor) == REDIS_ERR) return;if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptyscan)) == NULL ||checkType(c,o,REDIS_HASH)) return;scanGenericCommand(c,o,cursor); }

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